San Jose, CA 95121 Frost Dates
When can you plant in San Jose, CA?
Around 01/02 is the usual last spring frost, about 127 days away. The first fall frost typically arrives around 12/25, about 362 frost-free days later.
The USDA Plant Hardiness Zone Map puts San Jose in Zone 9b (25 to 30°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 17 weeks of growing season left in San Jose before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around San Jose's last frost
01/02 is the middle of 30 years of NOAA records, not a promise. Plant by 01/23 and you're betting against frost in roughly 9 years out of 10. 12/14 is the safer bet, historically only a 1-in-10 chance of frost that late.
How San Jose compares
At roughly 362 frost-free days, San Jose places 2,051 of 40,283 ZIP codes in this dataset. Within CA, it ranks 937 of 2,555.
Learn more
local microclimates covers what one yard in San Jose can differ from the 95121 normal. zone vs. frost date covers why Zone 9b and San Jose's frost date answer different questions.